Whenever we go to a festival - except in freak sunny weather circumstances - it's all about the jumpers, wellies and oversized parkas, to keep us just above freezing levels or from actually crying.

But celebs live in a very different, heated trailer kind of world, so why shouldn't they slip their smallest possible outfits on to dance around on stage looking all kinds of sexy?

Like when Ellie Goulding popped up to do her set. She'd just flown in from Cannes - swanky - where she'd sung at the AMFAR's Cinema Against Aids Gala hosted by Sharon Stone, with guests including everyone from Kylie Minogue to Nicole Kidman. Ellie admits to being starstruck at the event, saying: "It was a really great cause and an amazing party but it was one of those situations where you just keep thinking 'what on earth!'"

Ellie Goulding: she's not that innocent (Image: Rex Features)

But getting up on stage at Radio 1's Big Weekend proved to be much more Ellie's scene, with the singer telling the crowd: "Nice to see all your lovely faces. OK, I'm feeling a little bit more relaxed now. That's good. I was in a right stress." And it seemed she'd swapped her usual hipster style for something much less innocent, performing in a tiny bra top, hotpants/skirt and fishnet number Rihanna or Britney (back in the day) would be proud of (although she did have to give in and wear a black bomber jacket for part of it).

Someone else who wasn't afraid to tap into her sexy side was Iggy Azalea. The Aussie rapper wore a skimpy crop top and skirt which turned into hotpants combo (exciting), and at one point started doing rude things to herself, Madonna style. Golly. The last we heard the star was supposedly spending lots of time in Paris with Kanye West , much to girlfriend Kim's annoyance (kind of understand Kim's annoyance). And given her onstage antics we expect we'll be hearing a lot more about her soon.

We're sure there's a perfectly reasonable explanation for all this (Image: Getty Images)

Meanwhile The Saturdays brought the cutesy flirt factor, with Molly flaunting her cleavage in a very low cut yellow top and pink bra. Still it was hard for anyone - however booby - to draw attention from Frankie's baby bump, which went from moderate to massive at various points throughout the performance and had everyone mildly entranced as a result.

Boobs and bump stole the show at The Saturdays

The band were performing as a four piece, with new mum Rochelle off on her Saturday's maternity leave (Sat-ernity leave?), and looked glam in neon bright animal print combos (we especially like Una's fringey skirt). But fellow mum Una explained that it isn't quite the same, saying: "We do rehearse as a four. We've done a few shows now so we're getting used to it. It's never the same without Rochelle, without any member there." Maw, she'll be back soon guys. And then Frankie will be off. Oh well.